235/40R18 tires are in stock right now with 57 options spanning roughly 20 brands, from premium touring names to budget-friendly performance rubber. Every order ships free, across our full tire range, with Affirm financing available and fast delivery from a nationwide network. Whether you're replacing a worn set or upgrading, you'll find summer, all-season and winter choices in this size below.
Shop 235/40R18 Tires In Stock
Showing 36 in stock.
What 235/40R18 tires means
The code breaks down into exact measurements. The 235 is the section width in millimeters (about 9.25 inches at the widest point of the tire). The 40 is the aspect ratio, meaning the sidewall height equals 40% of the width — that works out to roughly 94 mm (about 3.7 inches). The R means radial construction, and the 18 is the wheel diameter in inches this tire mounts to.
Add it up and the overall tire diameter is about 25.4 inches, and the tire turns roughly 794 revolutions per mile. Those numbers matter to a buyer: the overall diameter affects speedometer accuracy and clearance, while the relatively short sidewall of a 40-series delivers crisp steering response at the cost of a firmer ride than a taller profile.
Vehicles & uses
This is a low-profile, 18-inch fitment that commonly appears on sports sedans and sport coupes where handling matters. As one size guide puts it, a 235/40R18 helps “match your vehicle's factory size while keeping handling crisp on many sedans and sports cars.” If your vehicle came with this size from the factory, staying with it preserves your speedometer calibration and intended feel. Always confirm the correct size and any load requirement against your door placard or owner's manual.
Brands & options in 235/40R18 tires
On the premium touring and performance end, Continental is well represented with the ContiProContact and the ProContact RX, including a ProContact RX SSR run-flat build. Hankook offers the Ventus S1 AS H125.
In the performance and daily-driver group, Kumho brings the Solus TA91 EV, Sumitomo the HTR AS P03, and Nexen the N'Fera AU7. Falken, Nitto, Toyo, Pirelli, Nokian and General round out the field.
For value-focused shoppers, GT Radial lists the CHAMPIRO UHP AS, Lexani the LXUHP-207, and Venom Power the Covert Grip ASP, alongside the budget Kenda KR400.
How to choose
Season
Summer tires give the sharpest dry and wet grip in warm weather but stiffen in the cold. All-season tires balance year-round usability, and dedicated winter tires (such as studless snow designs) are the choice for hard freezes and snow. Pick based on your climate, not just the calendar.
Treadwear & UTQG
The UTQG rating (treadwear, traction and temperature grades) helps you compare longevity and grip between tires. A higher treadwear number generally suggests longer life, while grippier performance compounds often wear faster.
Load index & speed rating
The load index and speed rating follow the size code (for example, the 91W and 95Y ratings seen in this size). Meet or exceed what your vehicle's placard specifies — never go below it.
Warranty
Mileage warranties vary by model and give a sense of expected tread life. Compare the coverage on any tire you're considering before you buy.
Frequently Asked Questions
What does 235/40R18 tires mean?
It's the size: 235 mm section width, a 40% aspect ratio sidewall (about 94 mm tall), radial construction, on an 18-inch wheel. Overall diameter is roughly 25.4 inches with about 794 revolutions per mile.
How much do 235/40R18 tires cost?
Prices currently range from about $86.37 to $510.00 per tire depending on brand, season and performance level.
How many 235/40R18 tires can I choose from?
There are 57 in stock across roughly 20 brands, including Continental, Hankook, Kumho, Nexen, Sumitomo, GT Radial, Lexani, Venom Power and more.